Enhancing high-rate plateau capacity of hard carbons by TiC-mediated closed pore formation and heterojunction engineering for sodium-ion batteries
作者：Feng G, Liu X, Xu C, et al.
關鍵字：TiC,Hard carbons,Closed pores,Heterojunctions,Plateau capacity
論文來源：期刊
發表時間：2025年
Fast-charging sodium-ion batteries with high energy density require hard carbons anodes that combine high low-voltage plateau capacity and rapid Na+ kinetics. However, simultaneously achieving these properties remains a critical challenging. Here, we utilize MXene as a structural modulator to create the closed-pore structure of hard carbons, enhancing Na storage while constructing TiC/C heterojunctions to accelerate Na+ transport. Unlike pure glucose-derived carbon, the MXene/TiC-embedded precursor induces curved graphite lattices and a moderately increased graphitization degree during carbonization, promoting formation of closed pores for dense sodium cluster storage. The resulting glucose/MXene-derived hard carbons (GM-HCs) exhibits a high reversible capacity of 381.4 mAh g-1 at 0.1C. Moreover, GM-HCs demonstrate remarkable low-voltage plateau capacity at high rate, retaining 124.9 mAh g-1 at 20C. Density functional theory (DFT) calculations confirm reduced Na+ diffusion barriers and enhanced electronic conductivity in hard carbons with TiC/C heterojunctions. When paired with a Na3V2O2(PO4)2F cathode, GM-HCs-based full cells deliver high energy density and stable cycling, retaining 95.2% capacity after 400 cycles. This work presents a dual strategy by creation of closed pores and construction of heterojunctions to simultaneously enhance plateau capacity and Na+ migration, advancing the development of high-performance sodium-ion battery anodes.